New Genetic Trigger That Can Renew Cells Responsible For Smell Discovered

December 7, 2011

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New Genetic Trigger That Can Renew Cells Responsible For Smell Discovered

According to a new study, neuroscientists from the University of California have discovered a genetic trigger that is able to stimulate the neurons from the nose that are responsible for smell to renew. With this study, the researchers believe that, in the future, pharmaceutical companies will be able to develop new therapies for people who have loss their sens of smell due to old age or trauma.

This gene is sending a message to the olfactory stem cells from the nose to differentiate into mature sensory neurons which are able to detect odors and to transmit the sensation to the brain.

“Anosmia the absence of smell is a vastly underappreciated public health problem in our aging population. Many people lose the will to eat, which can lead to malnutrition, because the ability to taste depends on our sense of smell, which often declines with age,” said neuroscientist John Ngai, who is the leader of this research. He also added that one of the reasons that may lead to anosmia is represented by the fact that once with the aging process the olfactory stem cells lose their capacity to replace mature sensory cells or maybe this mature cells are depleted. With the finding of this gene they also found a way to promote active stem cells to renew the sensory cells and to maintain this way the olfactory function.

This study is very useful because in the future the scientists could harness stem cells that are found in others sensory organs and will be able to recover the functions of sensory organs which are affected by degenerative disease or are injured.

Smell Sence

Sensory neurons from the nose that are responsible for smelling, live 30 day and then are replaced by new sensory neurons which are generated by the mature stem cells that are found in the olfactory epithelium. The key question for the scientist is what is the mechanism that make the stem cells to divide into mature and functional sensory cells which are responsible for odor.

“These stem cells are capable of reconstituting the entire sensory epithelium of the nose following injury, so understanding how these stem cells work is important for understanding the regeneration process that goes on in the nose.” Nagi said.

The researchers found, after screening the epithelial cells of the nose for regulatory genes, that a gene called p63 which is also known as a transcription factor that is controlling the regulatory genes for stem cells that are found in the skin, in the prostate and in the airway lining. By inactivating p63 gene in mice, the scientist were able to demonstrate that nasal stem cells can differentiate into adult sensory neurons that are responsible for smelling.

The researcher said that this gene, called p63 can secrete a molecule which will make the stem cells in the nose not only to differentiate, but also to self-renew. If the action of this molecule is stopped, then the stem cells will go into differentiation.

The scientist hope that in the future will be able to create a drug the regulates or modulates the p63 gene in order to increase the production of nasal stem cells therefore the number of mature smell neurons.

The p63 gene can be normally found in a wide range of epithelial tissues meaning that these results could be transpolated to other stem cells found in the skin leading therefore to new treatment options that could replace not only nervous damaged tissues but other epithelial tissues as well.